The coldest
planetary body in the Solar System is Triton, a moon of
Neptune.
(-235 °C or 38 K)

The lowest
temperatures in nature have been measured at Vostok,
Antarctica.
(-89 °C or 183 K)

Absolute
Zero

Physicists use a scale for
temperature that is directly related to the speed of
atoms. This is called the Absolute scale or the
Kelvin temperature scale. Lord Kelvin (William
Thomson) was a British physicist who developed the
scale in 1848. The zero point (0 K) is the lowest
possible temperature in the universe and is, hence,
called absolute zero.